> one can improve search performance by using a RAMDirectory created from an underlying FSDirectory using one of the parameterised constructors. Is this correct? Absolutly
> Will a FSDirectory not automatically load the index into memory provided enough RAM is available? Not all index files are loaded in the RAM if you are using the FSDirectory. Though at the same time, queries are cached. > Do I have to explicitly use a RAMDirectory? If you want to load the comeplte index in the memory, yes. This increase the performance a lot as it drastically reduces the number of disk IO. Obviously at the cost of the RAM. If you have enough RAM available to accommodate the complete index, you can go ahead with this. Regards, kapilChhabra -----Original Message----- From: Hardy Ferentschik [mailto:[EMAIL PROTECTED] Sent: Tuesday, November 27, 2007 12:25 PM To: java-user@lucene.apache.org Subject: RAMDirectory vs FSDirectory Hi there, I am using currently a FSDirectory to build my index. The reason for using a file system based index is that a full index rebuild takes around 30 minutes and I want to keep a persistent index. In 'Lucene in Action' I've read that one can improve search performance by using a RAMDirectory created from an underlying FSDirectory using one of the parameterised constructors. Is this correct? Will a FSDirectory not automatically load the index into memory provided enough RAM is available? Do I have to explicitly use a RAMDirectory? --Hardy --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
